Ok I thought I was going a bit crazy regarding image sharpness so I decided to do some A/B tests with my Pi2Jamma (Raspberry Pi Jamma Interface) which runs super resolutions 2560x240 and test it against my Groovyarcade Rig (ATI 4550 & vga cable to JPAC)

The results are quite obvious.

The Pi2Jamma looks sharp, you can almost count individual pixels.

With the Jpac the image looks soft, almost like it has anti-aliasing on.

Definitely, those filters are generally used to simulate a CRT on another display by introducing scanlines, phosphor glow, screen curvature, etc. to make a non-CRT display look more like a CRT. Those filters will introduce blurriness and other undesirables.

Ive also noticed noise around some text (once again this doesnt happen on my Pi2Jamma

It's quite severe in the image below around the word credit. There is definitely some blue/purple ghosting going on. I would usually agree and say that its an issue with the CRT but it doesnt happen on the Pi2Jamma :|

Hi Calamity, I had some troubles generating a log from the terminal, turns out i had to do it via KDE desktop, Log attached

Hi jimmyj1979,

The log looks perfect, I don't think it's a software issue cause by GLSL filters or incorrect scaling. The video mode is correctly set. The fact that you see artifacts on text rendering in MAME menus is normal, that part of MAME is not designed to work on low resolutions any more. However, regarding the game itself should look crisp.

If you want my opinion, the pictures you posted don't look too bad. I'd say most users would find them good enough. It's only that you have something else to compare. As you say, it looks like the analog chain is causing some signal quality loss.